MEMS Executive Congress 2014

MEMS Executive Congress 2014

What’s next for MEMS?By Paula Doe, SEMI

The proliferation of sensors into high volume consumer markets,
and into the emerging Internet of Things, is driving the MEMS market to
maturity, with a developed ecosystem to ease use and grow applications. But it
is also bringing plenty of demands for new technologies, and changes in how
companies will compete.

While the IoT may be all about
sensors, it is not necessarily a bonanza for most traditional MEMS sensor makers.
“The surprising winner turns to be optical MEMS for optical cross connect for
the data center, where big growth is coming,” said Jérémie
Bouchaud, IHS Director and Sr. Principal Analyst, MEMS & Sensors, at the
recent MEMS Executive Congress held in Scottsdale Arizona from November 5-7.

The market for
wearables will also see fast growth for the next five years, largely for smart
watches, driving demand for motion sensors, health sensors, sensor hubs and
software –but even in 2019 the market for sensors in wearables will remain
<5% the size of the phone/tablet market, IHS predicts. The greater IoT market may reach billions of
other connected devices in the next decade, but sensor demand will be very
fragmented and very commoditized. Smart homes may use 20 million sensors in
2018, but many other industrial applications will probably each use only
100,000 to 2-3 million sensors a year, Bouchaud noted.

And most of
this sensor market will be non-MEMS sensors, some mature and some emerging,
including light sensors, fingerprint sensors, pulse sensors, gas sensors, and
thermal sensors, all requiring different and varied manufacturing
technologies. Much of the new sensor
demand from automotive will be also be for non-MEMS radar and cameras, though
they will also add MEMS for higher performance gyros, lidar and
microbolometers, according to IHS. Expect major MEMS makers to diversify into
more of these other types of sensors.

Figure 1: Growth shifts to new types of sensors. (Source: IHS)

Yole
Développement CEO Jean Christophe Eloy looked at how the value in the IoT would
develop. While the emerging IoT market
is initially primarily a hardware market, with hardware sales climbing
healthily for the next five years or so, it will quickly become primarily a
software and services market. In five to
six years hardware sales will level off, and the majority of the value will
shift to data processing and value added services. This information service market will continue
to soar, to account for 75% of the $400 Billion IoT market by 2024.

Figure 2: Initial IoT growth will be from hardware, but most of value will eventually be software and services. (Source: Yole Développement)

Re-thinking the business models?

The IoT will bring big changes to the electronics industry,
from new technologies to new business models, as well as new market leaders,
suggested George Liu, TSMC Director of Corporate Development. He of
course also argued that the high volume and low costs required for connected
objects would drive sensor production to high volume foundries, while demand
for smart distributed processing wouldrequire more integration with CMOS and
give the advantage to CMOS makers.

Liu projected these changes will mean a new set of companies
will come out on top. Few leading system makers managed to successfully
transition from the PC era to the mobile handset era, or from the mobile
handset era to the smart phone era, as both the key technologies and the
winning business models changed, and chip makers faced disruption as well. “For
one thing, the business model changed from making everything in house to making
nothing,” he noted. “The challenge is to focus on where one is most efficient.”

“The odds of Apple or Google being the dominant players in
the next paradigm is zero,” concurred Chris Wasden, Executive Director,
Sorenson Center for Discovery and Innovation at the University of Utah.

Lots of other things will have to change to enable the IoT
as well. Liu projected that devices will need to operate at near threshold or
even sub-threshold voltages, with “thinner” processing overhead, while the
integration of more different functions will redefine the system-in-a-chip.
Smaller and lower cost devices will require new materials and new
architectures, new types of heterogeneous integration and wafer-level
packaging, and an ecosystem of standard open platforms to ease development.
TSMC’s own MEMS development kit has layout rules, but not yet behavioral rules,
always the more challenging issue for these mechanical structures. “That’s the
next big thing for us,” he asserted. “These huge gaps mean huge
opportunities.”

IDMs and systems companies still likely to dominate

Still, the wide variety, and sometimes tricky mechanics and
low volumes, of many MEMS devices have been a challenge for the volume
foundries. The fabless MEMS model has seen only limited success so far
and that’s unlikely to change drastically in the next decade either, countered
Jean Christophe Eloy, CEO of Yole Développement. He pointed out that some 75%
of the MEMS business is dominated by the four big IDMs who can drive costs down
with volumes and diversified product lines. To date, only two fabless
companies–InvenSense and Knowles—are among the top 30 MEMS suppliers.

Most of the rest of the top 30 are system makers with their
own fabs, making their own MEMS devices to enable higher value system products
of their own, which is likely to continue to remain a successful approach, as
the opportunities for adding value increasingly come from software, processers,
and systems. “MEMS value has always been at the system level,” noted
Eloy.

GE’s recent introduction of an improved MEMS RF switch to
significantly reduce the size and cost of its MRI systems is one compelling
example of systems-level value of MEMS, as the little MEMS component has the
potential to greatly extend the use of this high-contrast soft-tissue imaging
technology. Though the company sold off its general advanced sensors unit
last year to connector maker Amphenol Corp., it is still making its unique RF
switch using a special alloy in house in small volumes as a key enabler of its
high value MRI systems. These imagers work by aligning the spin of hydrogen
nuclei with a strong magnet, tipping them off axis with a strong RF pulse from
an antenna, then measuring how they snap back into alignment with lots of
localized antennas with low power RF switches close to the body. “We’re
now launching a new receive chain using MEMS RF switches,” reported Tim Nustad,
GM and CTO, Global Magnetic Resonance, GE Healthcare. “Later we can see a
flexible, light weight MRI blanket.”

Opportunity for smaller, lower power, lower cost
technologies

So far, MEMS makers have driven down the cost of devices by
continually shrinking the size of the die. But that may be about to
change, as the mechanical moving structures have about reached the limit of how
much smaller they can get and still produce the needed quality signal.
That’s opening the door for a new generation of devices using different sensing
structures and different manufacturing processes. For inertial sensors,
options include bulk acoustic wave sensing from Qualtre, piezoresistive
nanowires from Tronics and CEA/Leti, and even extrapolating gyroscope-like data
with software from accelerometers and magnetometers. MCube’s virtual gyro with
this approach, now in production with some design wins, claims to save 80% of
the power and 50% of the cost of a conventional MEMS gyro.

Piezoelectric sensing, often with PZT films, is also drawing
attention, with products in development for applications ranging from timing
devices to microphones. Sand9 claims lower noise and lower power for its
piezoelectric MEMS timing, now starting volume manufacturing for shipments in
1Q15. It has also recently received a patent for a piezo microphone,
while startup Vesper (formerly known as Baker-Calling and then Sonify) also
reports working with a major customer for its piezoelectric MEMS microphone.

More open platforms ease development of new applications
of established devices

Meanwhile, the maturing ecosystem of open development
platforms across the value chain is helping to ease commercialization of new
applications of existing MEMS devices. The two latest developments in this
infrastructure are a standard interface to connect all kinds of different
sensors to the controller, and an open library of basic sensor processing
software. The MIPI Alliance brought together major users and suppliers—ranging across
STMicroelectronics and InvenSense, to AMD and Intel, to Broadcom and Qualcomm,
to Cadence and Mentor Graphics—to agree on an interface specification to make
it easier for system designers to connect and manage a wide range of sensors
from multiple suppliers while minimizing power consumption of the
microcontroller. A collaboration ofsensor makers and researchers are also
making a selection of baseline algorithms available for open use to help more
users speed development of new applications. Offerings include
Freescale’s inertial sensor fusion and PNI Sensors’ heart rate monitoring
algorithms, along with other contributions from Analog Devices, Kionix, NIST,
UC Berkeley and Carnegie Mellon to start. The material will be available
through the MIG website.

Plenty of companies have also introduced their own
individual platforms to ease customer development tasks as well, ranging from
MEMS foundries’ inertial sensor manufacturing platforms to processor makers’
development boards and kits. Recently STMicroelectronics also adding its sensor
fusion and other software blocks to its development platform.

KegData is one example of a company making use of these
platforms to easedevelopment of a solution for a niche problem – an automated
system for telling pub owners how much beer is left in their kegs, using a
Freescale pressure sensor and development tools. Currently the only way to know
when a beer keg is empty is to go lift and weigh or shake it, a problem for
efficiently managing expensive refrigerated inventory. Adding a pressure
sensor in the coupler on top of the keg allows the height of the beer to be
measured by the differential pressure between the liquid and the gas above it.
The sensor then sends the information to a hub controller that communicates
with the internet, letting the pub manager know to order more, or even
automatically placing the order directly with the distributor. The
startup’s business model is to give the system to distributors for free, but
sell them the service of automating inventory management for their customers,
saving them the significant expense of sending drivers around to check the
inventory and take pre-orders.

More broadly, MEMS microphones are poised to continue to
find a wide range of new applications. IHS’ Bouchaud pointed out that
cars will soon each be using 12-14 MEMS microphone units, to listen for changes
in different conditions, while home security applications will use them to
detect security breaches from unusual patterns of sounds, from people in
the house to dogs barking. Startup MoboSens says it converts its chemical water
quality data into audio signals to feed it into the phone’s mic port for better
quality.

Opportunities still for new types of MEMS devices

Growth will also continue to come from new MEMS devices that
find additional ways to replace conventional mechanical parts with
silicon. Eloy noted that MEMS autofocus units may finally be
the next breakout device, as they have started shipping in the last few weeks,
and aim at shipping for products in 2015. MEMS microspeakers are also
making progress and could come soon. But ramping new devices to the high
volumes demanded by consumer markets is particularly challenging. “The only way
to enter the market is with new technology, but high volume consumer markets
make entry very hard for new devices,” he said. “The market is saturated, wins
depend on production costs, and not everyone can keep up…. The last significant
new device was the MEMS microphone, and that was ten years ago”.

But innovative new MEMS technologies also continue to be
developed for initial applications in higher margin industrial and biomedical
fields. One interesting new platform is the MEMS spectrometer from VTT
Technical Research Center of Finland. This robust tunable interferometer
essentially consists of an adjustable air gap between two mirrors, made of
alternating ALD or LPCVD bands of materials with different defraction indexes,
explained Anna Rissanen, VTT research team leader for MOEMS and bioMEMS
instruments. The structure can be tuned by different voltages to filter
particular bands of light, while a single-point detector, instead of the usual
array, enables very small and low cost spectrometers or hyper spectral cameras.
VTT spinout Spectral Engines is commercializing near-IR and mid-IR sensors
aimed at detecting moisture, hydrocarbons and gases in industrial
applications. Other programs have developed sensors for environmental
analysis by flyover by nano satellites and UAVs, sensors for monitoring fuel
quality to optimize energy use and prevent engine damage, and sensors that can
diagnose melanoma from a scan of the skin.